Metallurgy



R. A. LEwls METALLURGY Sept. 29, 1964 3 Sheetssheet 2 F1ed June 12, 1958 Which is above the fo SUTface of the aluIninun1 poo1 77 and iS adiacent electfolyfe 78, iS compriSed of Silicate bonded Si1icoI1 carbido bTicks. The lower poT-tion of Wa11 74, that iS, the poftion Which is be1ow fhe leve1 of n1olten alun1inuTn poo1 77, Inay be of ntfide bonded SiIicon cafbide bTick. IIovvevof, ffon a ooSt standpoint theSe bficks Inay be of the Silicate bonded silicon cafbide type aS is shown in FIGURE The Stfuctufe shown in F(1J1E S iS advantageouS in that it con1bifles the SUpefiof fesiSfanco of the nitfide bonded si1icon caTbide to atfack by o101ten a1uinUn1, Whi1e Sfi11 n1aintaining a o1ofe economica1 wan sffoctufe than if the WallS Wefe composed entifely of nitffde bonded silicon oafbido bfick.

vafiouS changeS and InodicationS of the inStant in vention n1ay be n1ade withont depaffing froIn the prin cipleS and spifit of the invention.

What iS claiIned iS:

1. AI1 electrolytic ce11 fof the foduction of aluII1inIlo1 coInpfising Z. vvallS of Silicon caTbide,

B- a bottoIn 11001' of feffactofy InateIial,

(1) said vya11s and oof dening a chambef adapted to contain a n1o1ten alufflinIlo1 pool i11 the 1ovef poffion of Said chan1ber and a body of nlo1ten e1ecffolyte in Said chambef above Said nlolten a1I1n1inu1 oo1 and in contact thefevvith,

(2) the poftion of said Wa11S adapted to bo ad iacent to the n1o1teI alUn1inun1 oo1 bein con1 pfiSed of nitride bonded silfcon carbide and the poftion above the alllIIinI1II1 pool and adapted to be adacent to fhe n1o1ten e1ectrolyte being coIn fised of si1icafe bonded si1icon oafbide,

C. at leaSt one anode Inen1bef disposed at 1eaSt paf tia11y Wifhi1 Said chaInbef and adapted to be par tially immefsed in said e1ectTolyte,

1). of leaSt one cathodio cnfTent conduofing e1eITleof spaced above Said f1oo1 extending thfongh one of said wallS and having ooo eXtfeInity oXtending oUt side the eleoffolyfic ce11 connecfed to a, oathodic buS SySteII1 and oIle exffeo1ity pfoieoting thTongh said nitride bonded si1icon calbide of said Wan and adapted to extend into Said pool of Inolten alu1inun1,

(1) at leaSt that poftion of the sufface of Said cLlfTet conducting elenlent consisting essentially of at least one of the Inafefials ffoIn the gfoup c()I1SiSti11g of the carbideS and bofides of titaniun1, ziTooniIln1, tanta1Ilo1 and niobiuIn.

Z. A p1UfoHty of e1ongated eleotrolytic cens fof the pfoduction of aluIninun1, Said cells being connected e1ec tTica11y in SeTies and being afranged iI1 side by Side fe 1ationShip With the side waHS of adjacent ceHS being in close pfoxiInity, each ce11 being comofiSed of Al a meta1 She11,

B, Side and end wanS of s1icon cafbide feffactofy dfS oSed Within Said ShelL 1) Said side wanS being fe1afively longef than Said end WanS,

(Z) Said Silico11 carbide feffacfofy of said Sido and end wal1s being contiguouS vvith said Sho1L C. a botton1 Hoof of Tefractofy IT1ateria1,

(1) Said SiC1e and end WaI1s and said f1oof defining an e1ongated ohan1bef adapted to confain a molten a1UIninum pool in the 1oWor poftion of Said chambef and a body of Inolten electfolyte in said chan1bef above Said Inolten poo1 and in contact thefevvith Z) the poftion of Said side and ond vva11S adapted fo be adjacont to the Inolten alnminum pool being coInprised of 11itfide bonded Silicon caf bido and the poTfion above the Ino1ten a1UnTinuIn poo1 and adapted to be adiacenf to the molten e1ectfolyte being compfiSed of si1icate bonded Silicon carbide,

1 at 1east one anode IneT1bef diSposed at 1eaSt paf tiany Within Said chambef and adapted to be paf tia1ly iInn1efsed iI1 Said e1ecfTolyto,

1- curTent conducting eleInentS pfojecting thIongh said nitfide bonded Si1icon cofbide of Said end va11S,

(1) each of Said cuffent condUcting e1oInents extendin thron h at leaSt one of Said vvallS and having ono extreII1ity extonding exfeIiofa11y of said She11 of Said e1ectro1yfic co11 connected to a cathodio bI1s systeIn and one extfeInity adapted to pfoject into Said poo1 of ololten aluIninum,

(Z) at 1eaSt that pofoon of the surface of Said o1en1ent to be in contact vith n1olten a1UIninun1 conSiSting eSSentiaHy of at 1east one of the TIlatefialS Selecfed ffon1 the group conSistiJg of the carbides and boTides of titaniI1n1, zifconiun1,

tanfalun1 and niobiuII1.

Refefences cifod in the 1o of thiS pafenf UNITED STATES PATENTS 1,714 081 FifZgefa1d May Z1, 1929 2,609,318 SWontze1 Sept. Z, 1952 Z 91S,44Z LowiS Dec. 1, 1959 2,92,60S Devanda Sept. 13, 1960 FoREIGN PATENTS 1,061,906 Ffance Apf. 16, 19S4 162,900 AI1Stralia May 18, 19S4 1,149,468 Ffance Deol 26, 19S7 

1. AN ELECTROLYTIC CELL FOR THE PRODUCTION OF ALUMINUM COMPRISING A. WALLS OF SILICON CARBIDE, B. A BOTTOM FLOOR OF REFRACTORY MATERIAL, (2) SAID WALLS AND FLOOR DEFINING A CHAMBER ADAPTED TO CONTAIN A MOLTEN ALUMINUM POOL IN THE LOWER PORTION OF SAID CHAMBER AND A BODY OF MOLTEN ELECTROLYTE IN SAID CHAMBER ABOVE SAID MOLTEN ALUMINUM POOL AND IN CONTACT THEREWITH, (2) THE PORTION OF SAID WALLS ADAPTED TO BE ADJACENT TO THE MOLTEN ALUMINUM POOL BEING COM PRISED OF NITRIDE BONDED SILICON CARBIDE AND THE PORTION ABOVE THE ALUMINUM POOL AND ADAPTED TO BE ADJACENT TO THE MOLTEN ELECTROLYTE BEING COMPRISED OF SILICATE BONDED SILICON CARBIDE, C. AT LEAST ONE ANODE MEMBER DISPOSED AT LEAST PARTIALLY WITHIN SAID CHAMBER AND ADAPTED TO BE PARTIALLY IMMERSED IN SAID ELECTROLYTE, D. AT LEAST ONE CATHODIC CURRENT CONDUCTING ELEMENT SPACED ABOVE SAID FLOOR EXTENDING THROUGH ONE OF SAID WALLS AND HAVING ONE EXTREMITY EXTENDING OUTSIDE THE ELECTROLYTIC CELL CONNECTED TO A CATHODIC BUS SYSTEM AND ONE EXTREMITY PROJECTING THROUGH SAID NITRIDE BONDED SILICON CARBIDE OF SAID WALL AND ADAPTED TO EXTEND INTO SAID POOL OF MOLTEN ALUMINUM, (1) AT LEAST THAT PORTION OF THE SURFACE OF SAID CURRENT CONDUCTING ELEMENT CONSISTING ESSENTIALLY OF AT LEAST ONE OF THE MATERIALS FROM THE GROUP CONSISTING OF THE CARBIDE AND BORIDES OF TITANIUM, ZIRCONIUM, TANTALUM AND NIOBIUM. 